Phase Diagram of the 2-Leg Heisenberg Ladder with Alternating Dimerization

TL;DR

This paper maps the phase diagram of a 2-leg antiferromagnetic Heisenberg ladder with alternating dimerization, identifying distinct phases and critical points using numerical methods, confirming previous theoretical predictions.

Contribution

It provides the first detailed numerical phase diagram of the model, validating conjectures from the nonlinear sigma model approach.

Findings

Identified a resonating valence bond phase and a dimer phase.

Located the critical line separating the phases.

Results agree with previous theoretical predictions.

Abstract

Using the Lanczos method we determine the phase diagram of the 2-leg AF-Heisenberg ladder with alternating dimerization. It consists of a resonating valence bond phase and a dimer phase separated by a critical line. Our results are in good agreement with previous conjectures obtained with the non linear sigma model.